Delayed Release Cysteamine Bead Formulation, and Methods of Making and Using Same

ABSTRACT

An enteric-coated bead dosage form of cysteamine, and related methods of manufacture and use, are disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

The benefit under 35 U.S.C. §119(e) of U.S. Provisional PatentApplication Ser. No. 61/835,965 filed Jun. 17, 2013, is hereby claimed,and the disclosure thereof is hereby incorporated by reference herein.

BACKGROUND

1. Field of the Disclosure

The disclosure relates generally to delayed release formulations ofcysteamine and pharmaceutically acceptable salts thereof, and relatedmethods of making and treatment, e.g. treatment of cystinosis and othermetabolic and neurodegenerative diseases including non-alcoholic fattyliver disease (NAFLD), Huntingon's disease, Parkinson's disease, RettSyndrome and others, use as free radical and radioprotectants, and ashepto-protectant agents. More particularly, the disclosure relates toenteric coated beads comprising cysteamine or a pharmaceuticallyacceptable salt thereof.

2. Brief Description of Related Technology

Cystinosis is a rare, autosomal recessive disease caused byintra-lysosomal accumulation of the amino acid cystine within varioustissues, including the spleen, liver, lymph nodes, kidney, bone marrow,and eyes. Nephropathic cystinosis is associated with kidney failure thatnecessitates kidney transplantation. A specific treatment fornephropathic cystinosis is the sulfhydryl agent, cysteamine. Cysteaminehas been shown to lower intracellular cystine levels, thereby reducingthe rate of progression of kidney failure in children.

An enterically-coated cysteamine composition has been described, forincreasing delivering of cysteamine to the small intestine and resultingin less frequent dosing compared to non enteric-coated cysteamine.

SUMMARY

One aspect of the disclosure provides a pharmaceutical dosage formincluding a plurality of cysteamine beads, the beads including a coreparticle including cysteamine or a pharmaceutically acceptable saltthereof and a pharmaceutically acceptable excipient, and an entericmembrane surrounding the core, wherein the plurality of beads ischaracterized by a distribution of particle sizes.

Another aspect of the disclosure provides a pharmaceutical dosage formincluding a plurality of cysteamine beads, the beads including a coreparticle including cysteamine or a pharmaceutically acceptable saltthereof and a pharmaceutically acceptable excipient, and an entericmembrane surrounding the core, wherein the plurality of beads ischaracterized by irregular bead shapes.

Yet another aspect of the disclosure provides a pharmaceutical dosageform including a plurality of cysteamine beads, the beads including acore particle including cysteamine or a pharmaceutically acceptable saltthereof and a pharmaceutically acceptable excipient, and an entericmembrane surrounding the core, wherein the plurality of beads ischaracterized by a distribution of enteric membrane thicknesses.

Still another aspect of the disclosure provides a method of making apharmaceutical dosage form, including any embodiment described herein,by a method including coating a core particle including cysteamine or apharmaceutically acceptable salt thereof and an excipient with anenteric polymer to form an enteric membrane. The method can includesorting core particles prior to enteric coating, to provide a selectedcore particle size distribution. The method can also include sortingenteric coated beads to provide a selected bead size distribution.

Yet another aspect of the disclosure provides a method for treating apatient in need of cysteamine comprising administering to the patient adosage form described herein, including any embodiment described herein.

Still another aspect of the disclosure provides dosage forms and relatedmethods according the disclosure herein wherein the primary activecomponent is cystamine rather than cysteamine or a pharmaceuticallyacceptable salt thereof.

For the compositions and methods described herein, optional features,including but not limited to components, compositional ranges thereof,substituents, conditions, and steps, are contemplated to be selectedfrom the various aspects, embodiments, and examples provided herein.

Further aspects and advantages will be apparent to those of ordinaryskill in the art from a review of the following detailed description.While the dosage form, method of making, and method of treatment aresusceptible of embodiments in various forms, the description hereafterincludes specific embodiments with the understanding that the disclosureis illustrative, and is not intended to limit the invention to thespecific embodiments described herein.

DETAILED DESCRIPTION

Described herein is pharmaceutical dosage form that includes a pluralityof cysteamine beads, the beads including a core particle includingcysteamine or a pharmaceutically acceptable salt thereof and apharmaceutically acceptable excipient, and an enteric membranesurrounding the core particle. The plurality of beads can becharacterized by a distribution of particle sizes. The plurality ofbeads can be characterized by irregular bead shapes. The plurality ofbeads can be characterized by a distribution of enteric membranethicknesses. Also disclosed herein are a method for the preparation ofthe dosage form, including coating a core particle including cysteamineor a pharmaceutically acceptable salt thereof and an excipient with anenteric polymer to form the enteric membrane. Optionally, the coreparticle can be formed by a wet granulation method. Optionally, granulesare sorted (e.g., via sieving) to a desired particle size range prior toenteric coating, and optionally again following enteric coating. Alsodisclosed herein are treatment methods including administering thedosage form to a patient in need thereof.

Cysteamine-containing, enteric-coated beads characterized by adistribution of particle sizes were shown to exhibit advantageouspharmacokinetics. Without intending to be bound by any particulartheory, it is contemplated that the pharmacokinetics are influenced bythe plurality of enteric-coated beads having a distribution of coreparticle sizes.

Cysteamine-containing, enteric-coated beads characterized by a irregularbead shapes were shown to exhibit advantageous pharmacokinetics. Withoutintending to be bound by any particular theory, it is contemplated thatthe pharmacokinetics are influenced by the plurality of enteric-coatedbeads having irregular bead shapes.

Cysteamine-containing, enteric-coated beads characterized by adistribution of enteric membrane thicknesses were shown to exhibitadvantageous pharmacokinetics. Without intending to be bound by anyparticular theory, it is contemplated that the pharmacokinetics areinfluenced by the plurality of enteric-coated beads having adistribution of enteric membrane thicknesses.

In one aspect the distribution of enteric membrane thicknesses can bestated in terms of weight gain of enteric membrane material based on thetotal weight of the coated beads. Thus, in one embodiment, thedistribution of enteric membrane thicknesses will be at least 2% basedon the total weight of the coated beads. In another embodiment, thedistribution of enteric membrane thicknesses will be at least 3%. Inanother embodiment, the distribution of enteric membrane thicknesseswill be at least 4%. In another embodiment, the distribution of entericmembrane thicknesses will be at least 5%. In another embodiment, thedistribution of enteric membrane thicknesses will be at least 6%. Inanother embodiment, the distribution of enteric membrane thicknesseswill be at least 7%. In another embodiment, the distribution of entericmembrane thicknesses will be at least 8%. In another embodiment, thedistribution of enteric membrane thicknesses will be at least 9%. Inanother embodiment, the distribution of enteric membrane thicknesseswill be at least 10%. In another embodiment, the distribution of entericmembrane thicknesses will be at least 11%. In another embodiment, thedistribution of enteric membrane thicknesses will be at least 12%. Inanother embodiment, the distribution of enteric membrane thicknesseswill be at least 13%. In another embodiment, the distribution of entericmembrane thicknesses will be at least 14%. For example, the differencein enteric membrane thickness from bead to bead can be in a range of+/−1-7% based on the total weight of the coated beads. The distributionof enteric membrane thicknesses can be in a range of about 2% to about14% based on the weight of the coated beads, or in a range of about 3%to about 13%, or in a range of about 4% to about 12%, or in a range ofabout 5% to about 11%, or in a range of about 6% to about 10%, or in arange of about 7% to 9%, or in a range of about 3% to 14%, or in a rangeof about 4% to 14%, or in a range of about 4% to 13%, or in a range ofabout 4% to about 12%, for example. In one embodiment, the absorption(AUC) of the dosage form when dosed orally is advantageously increased,compared to other dosage forms of cysteamine. Without intending to bebound by any particular theory, it is contemplated that the increase inabsorption is influenced by the dosage form exhibiting a pseudo-extendedrelease profile. The pseudo-extended release profile is contemplated tobe influenced by one or more factors, including a distribution ofenteric membrane thicknesses, a distribution of bead particle sizes, andthe beads having irregular bead shapes. For example, in an embodimentwherein the beads have a distribution of enteric membrane thicknesses,it is contemplated that for beads which have a relatively thin coating,the coating will completely dissolve at the trigger pH relativelyquickly to release the cysteamine composition, whereas for beads havinga relatively thick coating the coating will take somewhat longer tocompletely dissolve and release the cysteamine composition. In anotheraspect, in an embodiment where the beads have a distribution of particlesizes and/or irregular bead shapes, it is contemplated that the guttransit time of the beads could be varied due to bead size and/or shape,such that the transit time until reaching the enteric membranedissolution pH is varied, thus contributing to a pseudo-extended releaseprofile. In another embodiment, the dosage form exhibits substantiallyequivalent (e.g., bioequivalent) Cmax and/or AUC characteristics whenadministered orally inside a capsule shell or without a capsule shell.

The dosage form provides a progressive and predictable absorption curve.In one type of embodiment, the Tmax of the dosage form when dosed orallyis advantageously more stable on a dose-to-dose basis, because the beadsare individually enteric-coated. A predictable, consistent Tmax ishighly advantageous for accomplishing a more consistent, sustainedreduction of leukocyte cystine levels by use of cysteamine. For example,process-related variations in enteric membrane thickness or otherinfluences on enteric membrane dissolution will affect only a fractionof the cysteamine in the dosage form and will tend to lead to thepseudo-extended release behavior described above. In contrast,enteric-coated capsules comprising cysteamine microspheres exhibitedsignificant variability in absorption time from capsule to capsule.

In another embodiment, the dosage form exhibits advantageous storagestability, e.g. as measured by the amount of cystamine present followingstorage and/or by the total amount of related substances. The storagestability can be assessed following storage at typical ambientconditions (e.g. 25° C. and 40% relative humidity) or at acceleratedstability conditions involving increased temperature and/or humidity.

The dosage form and methods are contemplated to include embodimentsincluding any combination of one or more of the additional optionalelements, features, and steps further described below (including thoseshown in the figures and Examples), unless stated otherwise.

In jurisdictions that forbid the patenting of methods that are practicedon the human body, the meaning of “administering” of a composition to ahuman subject shall be restricted to prescribing a controlled substancethat a human subject will self-administer by any technique (e.g.,orally, inhalation, topical application, injection, insertion, etc.).The broadest reasonable interpretation that is consistent with laws orregulations defining patentable subject matter is intended. Injurisdictions that do not forbid the patenting of methods that arepracticed on the human body, the “administering” of compositionsincludes both methods practiced on the human body and also the foregoingactivities.

As used herein, the term “comprising” indicates the potential inclusionof other agents, elements, steps, or features, in addition to thosespecified.

As used herein, the term wt. % is the weight percent based on the totalweight, e.g. of the core particle, or enteric membrane, or total bead,as described in context. Unless stated otherwise, the wt. % is intendedto describe the weight percent based on dry weight (e.g., for a coreparticle following drying).

All ranges set forth herein include all possible subsets of ranges andany combinations of such subset ranges. By default, ranges are inclusiveof the stated endpoints, unless stated otherwise Where a range of valuesis provided, it is understood that each intervening value between theupper and lower limit of that range and any other stated or interveningvalue in that stated range, is encompassed within the disclosure. Theupper and lower limits of these smaller ranges may independently beincluded in the smaller ranges, and are also encompassed within thedisclosure, subject to any specifically excluded limit in the statedrange. Where the stated range includes one or both of the limits, rangesexcluding either or both of those included limits are also contemplatedto be part of the disclosure.

Unless expressly stated otherwise, all references to cysteamine hereinare intended to encompass pharmaceutically-acceptable salts thereof, andfor every reference to cysteamine herein the use of cysteaminebitartrate is specifically contemplated as an embodiment. As describedin the Summary above, embodiments of the dosage forms and methodsdescribed herein can employ cystamine as the primary active component,rather than cysteamine or a pharmaceutically acceptable salt thereof.

Unless expressly stated otherwise, reference herein to a bead andproperties thereof is intended to be interpreted as applying equally toa collection of beads (e.g., a plurality of such beads). Likewise,unless expressly stated otherwise, reference herein to a core particleand properties thereof is intended to be interpreted as applying equallyto a collection of core particles (e.g., a plurality of such coreparticles).

As described above, a pharmaceutical dosage form is contemplated thatincludes a plurality of cysteamine beads, the beads including a coreparticle including cysteamine or a pharmaceutically acceptable saltthereof and a pharmaceutically acceptable excipient, and an entericmembrane surrounding the core particle, wherein the plurality of beadsis characterized by a distribution of particle sizes.

In one embodiment, the particle sizes of the beads are in a range ofabout 0.7 mm to about 2.5 mm, or about 0.7 mm to about 2.8 mm, or about0.8 mm to about 1.7 mm. For example, the target bead size can be up to2.5 mm with no more than 10 percent variation over this size, to amaximum size of 2.8 mm.

As the particle size of the beads becomes too small, the variability incysteamine content increases. As the particle size becomes too large,the beads are too large for use in drug products that are labeled to beadministered via sprinkling (e.g., on applesauce or other soft foods,such as jellies) and swallowed without chewing, or administered via anenteral feeding tube. Also as the particle size increases, it was foundthat the larger particles get coated more than the smaller particles,resulting in lower relative assay when compared to use of smallerparticles. To compensate, relatively more such beads would be needed inorder to meet the label strength per capsule, but because salts such ascysteamine bitartrate already have a high molecular weight, filling acapsule shell with sufficient large particles to meet the label strengthper capsule becomes difficult or impossible (e.g. to fill a size 0capsule to a 75 mg strength of cysteamine free base). Accordingly thebead particle size in one type of embodiment is up to 1.7 mm.

The distribution of bead particle sizes for various non-exclusiveembodiments of the invention can be characterized in ways.

In one embodiment, the beads can be characterized by 5% or less of thebeads by weight being retained on a #12 mesh (1.68 mm) screen and 10% orless by weight passing through a #20 mesh (0.84 mm) screen. In anotherembodiment, at least 80% by weight of the beads have a particle size ina range of about 850 μm to about 1180 μm, e.g. as determined by sieving.

The distribution of bead sizes can be characterized by a gradation testvia analytical sieving. Thus, in another embodiment the distribution ofbead sizes is characterized by 0% of the beads being retained on a 1700μm sieve and less than 5% by weight of the beads being retained on a1400 μm sieve. Optionally less than 30% by weight of the beads areretained on a 1180 μm sieve. Optionally less than 70% by weight of thebeads are retained on a 1000 μm sieve. Optionally less than 20% byweight of the beads are retained on a 850 μm sieve. Optionally at least15% by weight of the beads are retained on a 1180 μm sieve. Optionallyat least 50% by weight of the beads are retained on a 1000 μm sieve.Optionally at least 10% by weight of the beads being retained on a 850μm sieve.

Thus, for example, the distribution can be characterized by 0% of thebeads being retained on a 1700 μm sieve and less than 5% by weight ofthe beads being retained on a 1400 μm sieve, and about 20% to about 30%by weight of the beads being retained on a 1180 μm sieve and then about50% to about 70% (or about 55% to about 65%) by weight of the beadsbeing retained on a 1000 μm sieve and then about 10% to about 20% byweight of the beads being retained on a 850 μm sieve.

In another embodiment, the distribution of bead sizes can becharacterized by a median particle size in a range of about 850 μm toabout 1180 μm.

The bead core particle can comprise one or more excipients. In one typeof embodiment, the excipients can include one or more fillers, binders,and surfactants. Other optional ingredients can include, but are notlimited to, glidants, lubricants, disintegrants, swelling agents, andantioxidants.

Fillers include, but are not limited to, lactose, saccharose, glucose,starch, microcrystalline cellulose, microfine cellulose, mannitol,sorbitol, calcium hydrogen phosphate, aluminum silicate, amorphoussilica, and sodium chloride, starch, and dibasic calcium phosphatedehydrate. In one type of embodiment, the filler is not water soluble,although it may absorb water. In one type of embodiment, the filler is aspheronization aid. Spheronization aids can include one or more ofcrospovidone, carrageenan, chitosan, pectinic acid, glycerides, β-CD,cellulose derivatives, microcrystalline cellulose, powdered cellulose,polyplasdone crospovidone, and polyethylene oxide. In one embodiment,the filler includes microcrystalline cellulose.

Binders include, but are not limited to, cellulose ethers, methylcellulose, ethyl cellulose, hydroxyethyl cellulose, propyl cellulose,hydroxypropyl cellulose, lower-substituted hydroxypropyl cellulose,hydroxypropylmethyl cellulose (hypromellose, e.g. hypromellose 2910,METHOCEL E), carboxymethyl cellulose, starch, pregelatinized starch,acacia, tragacanth, gelatine, polyvinyl pyrrolidone (povidone),cross-linked polyvinyl pyrrolidone, sodium alginate, microcrystallinecellulose, and lower-substituted hydroxypropyl cellulose. In oneembodiment, the binders are selected from wet binders. In one type ofembodiment, the binder is selected from cellulose ethers, e.g.hypromellose.

Surfactants include, but are not limited to, anionic surfactants,including sodium lauryl sulfate, sodium deoxycholate, dioctyl sodiumsulfosuccinate, and sodium stearyl fumarate, nonionic surfactants,including polyoxyethylene ethers, and polysorbate 80, and cationicsurfactants, including quaternary ammonium compounds. In one embodimentthe surfactant is selected from anionic surfactants, e.g. sodium laurylsulfate.

Disintegrants include, but are not limited to, starch, sodiumcross-linked carboxymethyl cellulose, carmellose sodium, carmellosecalcium, cross-linked polyvinyl pyrrolidone, and sodium starchglycolate, low-substituted hydroxypropyl cellulose, hydroxypropylstarch.

Glidants include, but are not limited to, polyethylene glycols ofvarious molecular weights, magnesium stearate, calcium stearate, calciumsilicate, fumed silicon dioxide, magnesium carbonate, magnesium laurylsulfate, aluminum stearate, stearic acid, palmitic acid, cetanol,stearol, and talc.

Lubricants include, but are not limited to, stearic acid, magnesiumstearate, calcium stearate, aluminum stearate, and siliconized talc.

The amount of cysteamine free base in the core particle can be at least10 wt. % or at least 15 wt. %, or at least 20 wt. %, or at least 25 wt.%, or at least 30 wt. %. For example, the amount of cysteaminebitartrate can be at least 50 wt. %, or at least 55 wt. %, or at least60 wt. %, or at least 65 wt. %, or at least 70 wt. %, or at least 75 wt.%, or at least 80 wt. %, or at least 85 wt. % of the core particle, forexample in a range of about 60 wt. % to about 90 wt. % or about 65 wt. %to about 85 wt. %. It is understood that any and all ranges includingthese values as endpoints is contemplated, for example, at least about15 wt. % to about 90 wt. %, or at least about 20 wt. % to about 85 wt.%, or at least about 30 wt. % to about 85 wt. %, or at least about 50wt. % to about 90 wt. %. As the dose of cysteamine free base can be upto about 2 g/m²/day, and the amount of free base is relatively smallcompared to the molecular weight of salts (e.g. the bitartrate salt) itis preferred that the core particle have as much active ingredient aspossible while allowing the creation and processing of core particles.

The amount of filler in the core particle is not particularly limited.In embodiments, the amount of filler (e.g. microcrystalline cellulose)can be in a range of about 10 wt. % to about 30 wt. %, or about 16 wt. %to about 23 wt. %, or at least 19 wt. % or at least 19.5 wt. %, forexample about 20 wt. %.

The amount of binder in the core particle is not particularly limited.In embodiments, the amount of binder (e.g. hypromellose) can be in arange of about 1 wt. % to about 10 wt. %, or about 2 wt. % to about 8wt. %, or about 4 wt. % to about 6 wt. %, for example about 5 wt. %.

The amount of surfactant, e.g. as a processing aid, in the core particleis not particularly limited. In embodiments, the amount of surfactant(e.g. microcrystalline cellulose) can be in a range of about 0.1 wt. %to about 1 wt. %, or about 0.2 wt. % to about 0.8 wt. %, or about 0.4wt. % to about 0.6 wt. %, for example about 0.5 wt. %.

The enteric (gastro-resistant) membrane material, e.g. polymer, can beone that will dissolve in intestinal juices at a pH level higher thanthat of the stomach, e.g. a pH of greater than 4.5, such as within thesmall intestine, and therefore permit release of the active substance inthe regions of the small intestine and substantially not in the upperportion of the GI tract. In one type of embodiment, the enteric materialbegins to dissolve in an aqueous solution at pH between about 4.5 toabout 5.5. In another type of embodiment, the enteric material rapidlydissolves in an aqueous solution at pH between of about 5. In anothertype of embodiment, the enteric material rapidly dissolves in an aqueoussolution at pH between of about 5.5.

For example, pH-sensitive materials will not undergo significantdissolution until the dosage form has emptied from the stomach. The pHof the small intestine gradually increases from about 4.5 to about 6.5in the duodenal bulb to about 7.2 in the distal portions of the smallintestine (ileum). In order to provide predictable dissolutioncorresponding to the small intestine transit time of about 3 hours(e.g., 2-3 hours) and permit reproducible release therein, the membraneshould begin to dissolve within the pH range of the duodenum, andcontinue to dissolve at the pH range within the small intestine.Therefore, the amount (thickness) of enteric membrane should besufficient to be substantially dissolved during the approximate threehour transit time within the small intestine (e.g., the proximal andmid-small intestine).

Enteric (gastro-resistant) materials can include, but are not limitedto, one or more of the following: cross-linked polyvinyl pyrrolidone;non-cross linked polyvinylpyrrolidone; hydroxypropylmethyl cellulosephthalate, hydroxypropylmethyl cellulose acetate succinate, celluloseacetate succinate; cellulose acetate phthalate, hydroxypropylmethylcellulose acetate succinate, cellulose acetate trimellitate; starchacetate phthalate; polyvinyl acetate phthalate; carboxymethyl cellulose;methyl cellulose phthalate; methyl cellulose succinate; methyl cellulosephthalate succinate; methyl cellulose phthalic acid half ester; ethylcellulose succinate; carboxymethylamide; potassiummethacrylatedivinylbenzene copolymer; polyvinylalcohols;polyoxyethyleneglycols; polyethylene glycol; sodium alginate;galactomannone; carboxypolymethylene; sodium carboxymethyl starch;copolymers of acrylic acid and/or methacrylic acid with a monomerselected from the following: methyl methacrylate, ethyl methacrylate,ethyl acrylate, butyl methacrylate, hexyl methacrylate, decylmethacrylate, lauryl methacrylate, phenyl methacrylate, methyl acrylate,isopropyl acrylate, isobutyl acrylate, or octadecyl acrylate, e.g.EUDRAGIT-L and -S series, including L 100-55, L 30 D-55, L 100, S 100, L12.5, and S 12.5, available from Evonik Industries; polyvinyl acetate;fats; oils; waxes; fatty alcohols; shellac; zein; gluten;ethylacrylate-maleic acid anhydride copolymer; maleic acidanhydride-vinyl methyl ether copolymer; styrol-maleic acid copolymer;2-ethyl-hexyl-acrylate maleic acid anhydride; crotonic acid-vinylacetate copolymer; glutaminic acid/glutamic acid ester copolymer;carboxymethylethylcellulose glycerol monooctanoate; polyarginine;poly(ethylene); poly(propylene); poly(ethylene oxide); poly(ethyleneterephthalate); poly(vinyl isobutyl ether); poly(vinyl chloride); andpolyurethane. A combination of enteric materials may also be used. Inone embodiment, the enteric material rapidly dissolves at pH 5.5 andhigher, to provide fast dissolution in the upper bowel. For example, theenteric material can be selected from a copolymer of methacrylic acidand methyl methacrylate, and a copolymer of methacrylic acid and ethylacrylate. For example, an enteric polymer is poly(methacrylic acidco-ethyl acrylate) 1:1 (EUDRAGIT L 30 D-55 and EUDRAGIT L100-55).

Examples of some enteric coatings are disclosed in U.S. Pat. No.5,225,202, including beeswax and glyceryl monostearate; beeswax, shellacand cellulose; and cetyl alcohol, mastic and shellac, as well as shellacand stearic acid (U.S. Pat. No. 2,809,918); polyvinyl acetate and ethylcellulose (U.S. Pat. No. 3,835,221); and neutral copolymer ofpolymethacrylic acid esters (Eudragit L30D) (F. W. Goodhart et al.,Pharm. Tech., pp. 64-71, April 1984); copolymers of methacrylic acid andmethacrylic acid methylester (Eudragits), or a neutral copolymer ofpolymethacrylic acid esters containing metallic stearates (Mehta et al.,U.S. Pat. Nos. 4,728,512 and 4,794,001). Such coatings comprise mixturesof fats and fatty acids, shellac and shellac derivatives and thecellulose acid phthlates, e.g., those having a free carboxyl content.See also Remington's Pharmaceutical Sciences, A. Osol, ed., Mack Pub.Co., Easton, Pa. (16th ed. 1980) at pages 1590-1593, and Zeitova et al.(U.S. Pat. No. 4,432,966), for descriptions of suitable enteric coatingcompositions.

One or more plasticizers can be added to enteric polymers in order toincrease their pliability and reduce brittleness, as it is known in theart. Suitable plasticizers are known in the art and include, forexample, butyl citrates, triethyl citrate, diethyl phthalate, dibutylsebacate, PEGs (e.g. PEG 6000), acetyl triethyl citrate, and triacetin.In one type of embodiment, the plasticizer is triethyl citrate. Whilesome enteric materials are flexible and do not require addition ofplasticizers, more brittle polymers (e.g., Eudragit L/S types, EudragitRL/RS, and Eudragit FS 30 D) benefit from plasticizers, e.g. in therange of 5 wt. % to 30 wt. % based on the dry polymer mass, e.g. about 8wt. % to about 12 wt. % triethyl citrate with poly(methacrylic acidco-ethyl acrylate) 1:1.

One or more anti-tacking agents (antiadherents) can also be added to anenteric coating mixture in order to reduce the tackiness of the film andprevent agglomeration, as it is known in the art. Anti-tacking agentsinclude talc, and glyceryl monostearate, fumed silica (e.g., AEROSIL200), precipitated silica (e.g., SIPERNAT PQ), and magnesium stearate,for example. Anti-tacking agents can be used in any suitable quantity,for example in a range of about 10 wt. % to 100 wt. % based on drypolymer mass, or about 10 wt. % to about 50 wt. %, or about 10 wt. % toabout 30 wt. %, or about 15 wt. % to about 30 wt. %. For example, in oneembodiment the amount of talc is in a range of 15 wt. % to about 30 wt.%, based on dry polymer mass.

One or more surfactants can also be added to an enteric coating mixturein order to improve substrate wettability and/or stabilize suspensions,as it is known in the art. Surfactants include Polysorbate 80, sorbitanmonooleate, and sodium dodecyl sulfate, for example.

The enteric membrane can be formed by any suitable process. Coatingprocesses include pan coating, fluid bed coating, and dry coating (e.g.,heat dry coating and electrostatic dry coating), for example. Pancoating and fluid bed coating using solvent are well establishedprocesses. In liquid coating, the enteric material and optionalexcipients (e.g. pigments, plasticizers, anti-tacking agents) are mixedin an organic solvent or water to form a solution or dispersion. Thecoating solution or dispersion is sprayed into solid dosage forms in apan coater or a fluid bed dryer and dried by hot air. For example, in aWurster fluid bed coating process, the coating fluid is sprayed from thebottom of the fluid bed apparatus, whereas in an alternative the coatingfluid is applied by top spraying, and in another alternative tangentialspray is applied.

The amount of enteric material applied is sufficient to achieve desiredacid resistance and release characteristics. For example, in oneembodiment the amount of enteric membrane will be sufficient to meetUnited States Pharmacopeia (USP) <711> requirements (USP 36-NF 31) fordelayed-release dosage forms, thereby not releasing 10.0 wt. % of drugafter 2 hours in 0.1N HCl. In another aspect, the formulation will besufficient to release at least 80% of the active in 20 minutes in pH 6.8buffer solution, e.g. using the dissolution method of USP 36-NF 31section <711>.

In one type of embodiment, the enteric membrane is present in an amountin a range of about 20% to 40%, or 25% to about 35% as measured by theweight gain compared to the uncoated particle cores, or in a range ofabout 25% to about 31% weight gain, or about 27% to about 31% weightgain, or about 28.5% to about 31% weight gain, based on the weight ofthe uncoated particle cores.

The beads with enteric membrane can be sorted (e.g., via sieving) to adesired particle size. In embodiments, the particle size range can beany particle size range or combination thereof described above inconnection with the core particles. In one type of embodiment, theparticle size range will be the same as the particle size range of theuncoated core particles. For example, the beads can be sieved such that5% or less of the bead core particles by weight are retained on a #12mesh (1.68 mm) screen and 10% or less by weight pass through a #20 mesh(0.84 mm) screen.

Additional lubricant (glidant, anti-tack agent) can be added to thecoated beads in powder form. Anti-tacking agents include talc, glycerylmonostearate, fumed silica (e.g., AEROSIL 200), and precipitated silica(e.g., SIPERNAT PQ), for example. For example talc powder can be addedto the coated beads, for example in an amount of 0.1 wt. % to about 1wt. % based on the total bead weight.

The formulation can include a capsule shell in which the beads aredisposed. Soft and hard capsule shells are known. In one embodiment, thecapsule shell is a hard capsule shell, e.g. a gelatin capsule shell or avegetable-based hard capsule shell.

Thus, for example, one type of embodiment combining various of thefeatures described above includes a pharmaceutical dosage form includinga plurality of cysteamine beads, the beads including a core particlecomprising cysteamine bitartrate, a filler (optionally microcrystallinecellulose), a binder (optionally hypromellose), and an enteric membrane(optionally Eudragit L30 D-55) surrounding the core, wherein theplurality of beads is characterized by a distribution of particle sizesin a range of about 0.7 mm to about 2.5 mm, wherein the enteric membraneis present in an amount in a range of about 20% to about 40% based onthe weight of the bead core particles, and wherein the beads aredisposed in a capsule shell.

Pharmacokinetics

As mentioned above, the dosage form can advantageously be designed haveone or more pharmacokinetic characteristics, e.g. in humans.

In one embodiment, the pharmaceutical dosage form is characterized by amean Tmax upon oral dosing, fasted, of greater than 75 minutes, or atleast 110 minutes, or at least 2 hours, or at least 3 hours, or in arange of about 2.2 hours to about 3.48 hours, or about 2.22 hours toabout 3.34 hours, or about 2.78 hours, or a Tmax in a range of 80% to125%, or 80% to 120% of such reference Tmax.

In another embodiment, the pharmaceutical dosage form is characterizedby a mean Cmax upon oral dosing, fasted, in a range of about 22.16μmol/L to about 34.63 μmol/L, or about 22.16 μmol/L to about 33.24μmol/L, or about 22.7 μmol/L, normalized to a 450 mg dose, or a Cmax ina range of 80% to 125%, or 80% to 120% of such reference Cmax. Inanother embodiment, the pharmaceutical dosage form is characterized by amean Cmax_D upon oral dosing in a range of about 0.004 to about 0.006mg/L/mg.

In another embodiment, the pharmaceutical dosage form is characterizedby a mean AUC (0-6 hours) upon oral dosing, fasted, in a range of about60.74 μmol·h/L to about 94.91 μmol·h/L, or about 60.74 μmol·h/L to about91.12 μmol·h/L, or about 75.93 μmol·h/L, normalized to a 450 mg dose, ora bioequivalent AUC (0-6 hours) in a range of 80% to 125%, or 80% to120% of such reference AUC (0-6 hours). In another embodiment, thepharmaceutical dosage form is characterized by a mean AUC (0-12 hours)upon oral dosing in a range of about 79.41 μmol·h/L to about 124.08μmol·h/L, or about 79.41 μmol·h/L to about 119.11 μmol·h/L, or about99.26 μmol·h/L, normalized to a 450 mg dose, or a bioequivalent AUC(0-12 hours) in a range of 80% to 125%, or 80% to 120% of such referenceAUC (0-12 hours). In another embodiment, the pharmaceutical dosage formis characterized by a mean AUC (0-inf_D) upon oral dosing in a range ofabout 0.86 min·mg/L/mg to about 1.35 min·mg/L/mg, or about 0.86min·mg/L/mg to about 1.3 min·mg/L/mg, or a bioequivalent AUC (0-inf_D)in a range of 80% to 125%, or 80% to 120% of such reference AUC(0-inf_D).

In example embodiments, any of the described pharmaceutical dosage formscan be characterized by providing mean pharmacokinetic parameters uponoral dosing, fasted, of: Tmax 183±90 minutes, Cmax 3.5±1.7 mg/L, and/orAUC (0-inf_D) 1.08±0.46 min*mg/L/mg, or a bioequivalent Tmax, Cmax orAUC in a range of 80% to 125%, or 80% to 120% of such referenceparameter.

In example embodiments, any of the described pharmaceutical dosage formscan be characterized by providing mean pharmacokinetic parameters uponoral dosing of the whole capsule, fasted, of: Tmax 194±38 minutes, Cmax2.3±0 mg/L, and/or AUC (0-inf_D) 0.84±0.19 min*mg/L/mg, or abioequivalent Tmax, Cmax or AUC in a range of 80% to 125%, or 80% to120% of such reference parameter; and/or mean pharmacokinetic parametersupon oral dosing of the beads, sprinkled on applesauce, of: Tmax 190±61minutes, Cmax 2.3±0.7 mg/L, and/or AUC (0-inf_D) 0.85±0.21 min*mg/L/mg,or a bioequivalent Tmax, Cmax or AUC in a range of 80% to 125%, or 80%to 120% of such reference parameter.

In another embodiment, the pharmaceutical dosage form is characterizedby being bioequivalent when administered orally, fasted, in a hardcapsule shell compared to the beads being administered orally, fasted,without a capsule shell. For example, the pharmaceutical dosage form canbe characterized by the dosage form when administered orally in a hardcapsule shell exhibiting a Cmax in a range of 80% to 125%, or 80% to120%, of Cmax exhibited by the beads administered orally without acapsule shell. In another embodiment, the dosage form can becharacterized by the dosage form when administered orally in a hardcapsule shell exhibiting an AUC (0-12 h) or AUC (0-inf) in a range of80% to 125%, or 80% to 120%, of that exhibited by the beads administeredorally without a capsule shell, respectively. In one embodiment, boththe Cmax and the AUC are within the tolerance ranges just described.

Purity

In one type of embodiment, the dosage form is characterized by havingless than 5 wt. % cystamine, based on the amount of cysteamine, asdetermined by reverse phase HPLC with UV detection, as described herein.In other embodiments, the dosage form is characterized by having lessthan 5 wt. % cystamine, based on the amount of cysteamine, following 12months storage at 25° C. and 40% relative humidity (RH), optionally asdetermined by reverse phase HPLC with UV detection, as described herein.In another type of embodiment, the dosage form is characterized byhaving less than 5 wt. % cystamine, based on the amount of cysteamine,following 18 months storage at 25° C. and 40% RH optionally asdetermined by reverse phase HPLC with UV detection, as described herein.In another type of embodiment, the dosage form is characterized byhaving less than 5 wt. % cystamine, based on the amount of cysteamine,following 24 months storage at 25° C. and 40% RH optionally asdetermined by reverse phase HPLC with UV detection, as described herein.In another type of embodiment, the dosage form is characterized byhaving less than 5 wt. % cystamine, based on the amount of cysteamine,following 30 months storage, or more, at 25° C. and 40% RH optionally asdetermined by reverse phase HPLC with UV detection, as described herein.Examples of suitable reverse phase HPLC assays are described herein.

In another type of embodiment, the dosage form is characterized byhaving less than 5 wt. % cystamine, based on the amount of cysteamine,following 12 months storage at 25° C. and 60% RH, optionally asdetermined by reverse phase HPLC with UV detection, as described herein.In another type of embodiment, the dosage form is characterized byhaving less than 5 wt. % cystamine, based on the amount of cysteamine,following 18 months storage at 25° C. and 60% RH, optionally asdetermined by reverse phase HPLC with UV detection, as described herein.In another type of embodiment, the dosage form is characterized byhaving less than 5 wt. % cystamine, based on the amount of cysteamine,following 24 months storage, or more, at 25° C. and 60% RH, optionallyas determined by reverse phase HPLC with UV detection, as describedherein.

In another type of embodiment, the dosage form is characterized byhaving less than 5 wt. % cystamine, based on the amount of cysteamine,following 3 months storage at 40° C. and 75% RH, optionally asdetermined by reverse phase HPLC with UV detection, as described herein.In another type of embodiment, the dosage form is characterized byhaving less than 5 wt. % cystamine, based on the amount of cysteamine,following 6 months storage at 40° C. and 75% RH, optionally asdetermined by reverse phase HPLC with UV detection, as described herein.

Any of the foregoing embodiments can be further characterized by havingless than 8 wt. % total related substances (impurities) based on theamount of cysteamine, under the described storage conditions and timesbased on reverse phase HPLC with UV detection, as described herein.

Method of Making

Also contemplated is a method for the preparation of a dosage formaccording to the disclosure here, including coating a core particlecomprising cysteamine or a pharmaceutically acceptable salt thereof andan excipient with an enteric polymer to form the enteric membrane.

The core particle including cysteamine or a pharmaceutically acceptablesalt thereof can be formed by any suitable process. In one embodiment,the core particle is formed by granulating a mixture of cysteamine or apharmaceutically acceptable salt thereof with an excipient and millingto a desired particle size range. In another embodiment, the coreparticle can be formed by extrusion and spheronization of a mixture ofcysteamine or a pharmaceutically acceptable salt thereof with anexcipient. Granulating processes can include fluid bed granulation, wetgranulation, hot melt granulation, and spray congealing, for example.Other processes include slugging and roller compaction. As it is knownin the art, the mixtures which are to be granulated can first bedry-blended. The dry-blended dry ingredients can be mixed with water,prior to extrusion.

It has been found that extrusion and spheronization of a mixture ofcysteamine or a pharmaceutically acceptable salt thereof with anexcipient can provide desirable core particles with a distribution ofparticle sizes as described herein and one or more other desirableproperties. Cysteamine bitartrate oxidizes in air and in water, and withheat. Thus, short processing times can lead to a more stable product.For example, reducing the amount of spheronization reduces the amount offriction and related heat. For example, reducing the amount of time thatthe product is exposed to air (either in the moist state and/or beforepackaging) also reduces the amount of oxidation. On the other hand,rapid processing by extrusion and spheronization can lead to a poorquality product, for example in having a large fraction of the pelletcores falling outside a desired particle size range. The amount ofmoisture absorbed by spheronization aids (which does not happenimmediately, but instead over time) influences the spheronizationcharacteristics of the beads. Accordingly, it was determined that themoisture content of the wet mass, the related wet hold time for swellingof spheronization aid(s), and the spheronization time are parametersthat can be optimized to achieve both good product yield, for example ina particle size range described herein, while maintaining goodstability, e.g. not more than 5 wt. % cystamine based on the amount ofcysteamine, as described herein.

Accordingly, in one embodiment the moisture content of the granulationmixture, prior to drying, is in a range of about 20 wt. % to about 40wt. %, or 25 wt. % to about 35 wt. %, or about 28 wt. % to about 32 wt.%, or at least about 28 wt. %, or at least about 28.5, or at least about20 wt. % to about 40 wt. %, or at least about 25 wt. % to about 35 wt.%, or at least about 27 wt. % to about 31 wt. % or at least about 28.5wt. % to about 31 wt. %.

The wet mass can be held for a period of time prior to extrusion, e.g.in order to allow the sphronization aid to swell with granulating fluid.The hold time can be at least 15 minutes, at least 30 minutes, at least45 minutes, or at least 60 minutes, for example. The hold time can be ina range of about 15 minutes to about 120 minutes, or about 30 minutes to100 minutes, or 60 minutes to 90 minutes, for example.

As described above in connection with description of the core particles,the method can include a step of sorting (e.g., by sieving) the coreparticles prior to enteric coating, to retain particles in apredetermined size range, for example sizes in a range of about 0.7 mmto about 2.8 mm, or about 0.7 mm to about 2.5 mm, or about 0.8 mm toabout 1.7 mm, or any range described above in connection with the coreparticles.

As described above in connection with description of the beads, themethod can include a step of sorting (e.g., by sieving) the beads afterenteric coating, to retain particles in a predetermined size range, forexample sizes in a range of about 0.7 mm to about 2.8 mm, or about 0.7mm to about 2.5 mm, or about 0.8 mm to about 1.7 mm, or any rangedescribed above in connection with the core particles.

In an extrusion and spheronization process, the following optionalfeatures can be employed, individually or in one or more combinationsthereof. Water can be used as a granulation agent. Microcrystallinecellulose can be used in the core particles as a spheronization aid.Hypromellose can be included in the core particles as a binder. Theextrusion screen size can be 1.0 mm. The friction plate of thespheronizer can be cross-hatched. The friction plate of the spheronizercan be cross-hatched with a square pitch of at least 3 mm, or greaterthan 3 mm, or at least 4 mm, or greater than 4 mm, or in a range ofabout 3 mm to about 7 mm, or about 5 mm. The spheronization time can beless than about 5 minutes, or less than about 4 minutes, or less thanabout 3 minutes, or less than about 2 minutes, or up to 1 minute. Thespheronized particles can include non-spherical particles (i.e.irregular shapes), e.g. a substantial fraction thereof, e.g. at least 20wt. % or at least 30 wt. %, or at least 40 wt. % or at least 50 wt. % orat least 60 wt. %, or at least 70 wt. % thereof.

The beads and/or filled capsules can be stored with a desiccant. Thebeads and/or filled capsules can be stored with an oxygen absorber.

For example, one embodiment of the method combining various of theparameters described above includes a method for the preparation of apharmaceutical dosage form including cysteamine beads, including forminga wet mass comprising cysteamine bitartrate and an excipient, optionallymicrocrystalline cellulose, with a moisture content in a range of in arange of about 20 wt. % to about 40 wt. %, extruding and spheronizingthe wet mass including cysteamine bitartrate and excipient to make coreparticles, sorting the core particles to a target particle size range,optionally 0.7 mm to 2.5 mm, coating the sorted core particles with anenteric polymer to form including beads comprising a core particle andan enteric membrane, and sorting the bead particles to a target particlesize range, optionally 0.7 mm to 2.5 mm.

Use/Administration

For administration of the dosage form, a total weight in the range ofapproximately 100 mg to 1000 mg (based on the free base) can be used.The dosage form can be orally administered to a patient suffering from acondition for which an cysteamine is indicated, including, but notlimited to, cystinosis and other metabolic and neurodegenerativediseases including non-alcoholic fatty liver disease (NAFLD),Huntingon's disease, Parkinson's disease, Rett Syndrome and others, useas free radical and radioprotectants, and as hepto-protectant agents. Inany method described herein, the treatment of humans is contemplated.The compositions of the disclosure can be used in combination with othertherapies useful for treating cystinosis and neurodegenerative diseasesand disorders. For example, indomethacin therapy (Indocid® or Endol®) isan anti-inflammatory used to treat rheumatoid arthritis and lumbago, butit can be used to reduce water and electrolyte urine loss. In childrenwith cystinosis, indomethacin reduces the urine volume and thereforeliquid consumption by about 30%, sometimes by half. In most cases thisis associated with an appetite improvement. Indomethacin treatment isgenerally followed for several years.

Other therapies can be combined with the methods and compositions of thedisclosure to treat diseases and disorders that are attributed or resultfrom cystinosis. Urinary phosphorus loss, for example, entails rickets,and it may be necessary to give a phosphorus supplement. Carnitine islost in the urine and blood levels are low. Carnitine allows fat to beused by the muscles to provide energy. Hormone supplementation issometimes necessary. Sometimes the thyroid gland will not produce enoughthyroid hormones. This is given as thyroxin (drops or tablets). Insulintreatment is sometimes necessary if diabetes appears, when the pancreasdoes not produce enough insulin. These treatments have become rarelynecessary in children whom are treated with cysteamine, since thetreatment protects the thyroid and the pancreas. Some adolescent boysrequire a testosterone treatment if puberty is late. Growth hormonetherapy may be indicated if growth is not sufficient despite a goodhydro electrolytes balance. Accordingly, such therapies can be combinedwith the compositions and methods disclosed herein.

The effectiveness of a method or composition of the disclosure can beassessed by measuring leukocyte cystine concentrations. Dosageadjustment and therapy can be made by a medical specialist dependingupon, for example, the concentration of cystine in leukocytes and theability to tolerate the drug. Additional therapies including the use ofomeprazole (Prilosec®) can reduce side effects of cysteamineadministration, such as abdominal pain, heartburn, nausea, vomiting, andanorexia, which can result from cysteamine-induced gastric acidhypersecretion, for example.

In addition, various prodrugs can be “activated” by use of theenterically coated cysteamine. Prodrugs are pharmacologically inert,they themselves do not work in the body, but once they have beenabsorbed, the prodrug decomposes. The prodrug approach has been usedsuccessfully in a number of therapeutic areas including antibiotics,antihistamines and ulcer treatments. The advantage of using prodrugs isthat the active agent is chemically camouflaged and no active agent isreleased until the drug has passed out of the gut and into the cells ofthe body. For example, a number of prodrugs use S—S bonds. Weak reducingagents, such as cysteamine, reduce these bonds and release the drug.Accordingly, the compositions of the disclosure are useful incombination with pro-drugs for timed release of the drug. In thisaspect, a pro-drug can be administered followed by administration of anenterically coated cysteamine composition of the invention (at a desiredtime) to activate the pro-drug.

EXAMPLES

The following examples are provided for illustration and are notintended to limit the scope of the invention.

Example 1 Bead Production

Cysteamine bitartrate and excipients (microcrystalline cellulose,hypromellose, sodium lauryl sulfate) were milled through a Comilequipped with a 0.094″ (2.3876 mm) screen operating at 500 RPM. Theamount of each ingredient (per 75 mg cysteamine capsule) is cysteaminebitartrate 258 mg+/−37.0 mg; microcrystalline cellulose 67.1 mg+/−9.6mg; hypromellose 17.2 mg+/−2.5 mg; and sodium lauryl sulfate 1.75mg+/0.25 mg. Cysteamine bitartrate was passed through the Comil firstfollowed by the excipients (hypromellose 2910-5, sodium lauryl sulfate,and microcrystalline cellulose). Cysteamine bitartrate and theexcipients were dry blended for approximately 15 minutes. While mixingat a setpoint speed of 47 rpm, purified water was slowly added (additionin approximately 4 minutes) into the blended components. After the wateraddition, the wet blend was mixed for an additional minute for a totalof 5 minutes.

A sample of the wet blend was collected and moisture content wasdetermined by loss on drying (LOD). The wet mass was discharged inpolyethylene lined fiber drums and held for 60-90 minutes prior toextrusion/spheronization.

The granulated wet mass was loaded onto a NICA extruder equipped with a1.0 mm screen at a feeder speed of 100 RPM setpoint and extruded at asetpoint speed of 55 RPM (50-60 RPM). The extruded product wasimmediately spheronized using a NICA Spheronizer equipped with 5.0 mmcross-hatched friction plates. Spheronization was performed at a targetspeed of 625 RPM (500-700 RPM) for 40-60 seconds. The particles werecollected in double polyethylene lined fiber drums and stored at roomtemperature for further processing.

The wet particles were dried in a Niro fluid bed dryer with an inlet airtemperature setpoint of 70° C. (60-80° C.). Drying was complete when themoisture content of uncrushed particles reached ≦1.0% w/w by LOD.Sampling of the particles began when the outlet air temperature reachedapproximately 50° C. and continued until the acceptance criterion of≦1.0%. The dried particles were transferred to fiber drums lined withdouble polyethylene bags and stored at room temperature.

The dried particles were screened through a #12 mesh screen and a #20mesh screen. Particles passing through the #12 mesh and retained on the#20 mesh were collected as product in double polyethylene linedcontainers with desiccant and oxygen absorber packets in the outerliner. The collected product may be re-passed through the screens asneeded. Particles greater than #12 mesh and less than #20 mesh were notretained as product for coating.

An enteric coating solution of Eudragit L30 D-55, triethyl citrate, andtalc in purified water was prepared in a mixing tank equipped with apropeller mixer and placed on a balance. Eudragit L 30 D-55 was added tothe portable mixing tank through a 60-mesh screen. The final solutionwas mixed for a minimum of 30 minutes and mixed continuously during thecoating process. Based on a 75 mg cysteamine capsule, the amounts ofcoating ingredients were: Eudragit L30 D-55 66.2 mg+/−9.5 mg; triethylcitrate 6.65 mg+/−0.95 mg; talc 15.3 mg+/−2.2 mg.

Spray lines connecting the portable mixing tank to the Niro fluid beddryer were primed. The floor balance was tared prior to starting thecoating process. The amount of coating solution sprayed was calculatedas the amount required to increase the core particle weight by 25%.

The core particles were loaded into the Niro fluid bed dryer equippedwith a Precision Coater which sprays from the bottom, 1.0 mm Nozzle, 30mm Swirl Accelerator, and 300 μm Filter Bonnet. The coating processparameters are provided in the table below.

Parameter Setpoint Range Inlet Air Volume 450 scfm 300-600 scfm InletAir Temperature 60° C. 45-75° C. Product Temperature 30° C. 25-45° C.Solution Spray Rate 0.220 kg/minute 0.200-0.240 kg/minute AtomizationAir Pressure 36 psi 32-40 psi

Once the target weight of coating solution was applied (25% of dryparticle weight), the beads were weighed to confirm weight increase of≧25.0%. If the weight was not ≧25.0% of the uncoated particle weight,the coating process was continued until ≧25.0% was achieved.

The coated beads were dried at an inlet temperature setpoint of 45° C.(35-55° C.) and inlet air volume setpoint of 350 scfm (300-400 scfm)until the LOD of the coated beads was ≦2.0% w/w. Once the LOD wasreached, the inlet air heating was turned off and the beads werecirculated at an air inlet volume of 300-400 scfm until the producttemperature reached not more than (NMT) 30° C.

The weight gain of the dried coated beads was calculated to confirm amaximum weight gain of ≦31.0% was achieved. Visual inspection confirmedthat the enteric membrane thickness was not consistent bead-to-bead, butinstead there was a distribution of enteric membrane thicknesses.

The dried coated beads were screened through a #12 mesh and a #20 meshscreen in sequence. Beads passing through the #12 mesh screen andretained on the #20 mesh screen were collected as product in doublepolyethylene lined fiber drums with a desiccant and oxygen absorbercanister in the outer liner. Mesh analysis testing can be performed asan in-process test to confirm the beads are within the limits of: NMT 5%are retained on a #12 mesh screen (1.68 mm) and NMT 10% pass through a#20 mesh screen (0.84 mm). If results are not within the limits, theproduct can be sorted by rescreening until the mesh analysis resultsmeet the specified limits.

The dried coated beads were lubricated with talc prior to encapsulation.The coated beads were loaded in a V-blender; talc powder was added tothe coated beads (calculated as 0.5% w/w of the total coated beadweight). The contents were mixed for a minimum of five minutes. Thelubricated coated beads were transferred to double polyethylene linedfiber drums with desiccant and oxygen absorber packets in the outerliner and stored at room temperature. Lubricated coated beads were usedin the manufacture of 75 mg size 0 capsules and 25 mg size 3 capsules.One batch of coated beads can be filled as a 75 mg strength batch or canbe split to fill both 75 mg and 25 mg strengths, for example.

The 75 mg hard gelatin capsules were filled using an automatedencapsulator at a speed of 80-100 spm to the target fill weightcalculated to achieve 75 mg cysteamine free base per capsule. The 25 mghard gelatin capsules were also filled with an automated encapsulator ata speed of 50-70 spm. The beads were introduced into the encapsulationprocess with a hopper.

Example 2 Particle Size Distribution

Several lots of cysteamine bitartrate enteric-coated beads produced viaan extrusion and spheronization process as described herein wereanalyzed for particle size distribution via analytical sieving. Theresults are tabulated below.

Sieve % Retained % Retained % Retained % Retained Size (μm) Lot A Lot BLot C Lot D 1700 0 0 0 0 1400 1.4 3.2 3.2 1.2 1180 19.5 25.7 26.7 20.31000 61.9 55.5 56 62 850 16.1 14.2 13.5 15.1 <850 1.2 1.4 0.6 1.4

Example 3 Pharmacokinetics

A population PK study was performed using Cystagon® and capsules ofcysteamine bitartrate gastro-resistant beads (CBGB) produced accordingto the method of Example 1 herein.

Pharmacokinetic (PK) and pharmacodynamic (PD) relationships following asingle dose of CBGB capsules was first studied in comparison to a singledose of immediate-release cysteamine bitartrate in a study with 9patients. Following normalization to a 450 mg dose, the maximum plasmalevels C max, AUC 0-6 h and AUC 0-12 h (calculated directly from theplasma level data for CBGB and from doubling the AUC 0-6 h value forimmediate-release cysteamine to represent two doses) were lower for CBGB(27.70±14.99 μmol/L, 75.93±39.22 μmol*h/L and 99.26±44.21 μmol*h/Lrespectively) than for immediate-release cysteamine bitartrate(37.72±12.10 μmol/L, 96.00±37.81 μmol*h/L and 192.00±75.62 μmol*h/Lrespectively. The pharmacokinetics of CBGB are consistent with adelayed-release formulation showing a T max of 2.78±1.56 h for CBGBcysteamine was moderately bound to human plasma proteins, predominantlyto albumin, with mean protein binding of about 52%. Plasma proteinbinding was independent of concentration over the concentration rangeachieved clinically with the recommended doses.

Additional studies were carried out as follows.

CBGB-A Study

Cystagon® Treatment Assignment: one (1) pre-dose PD sample was collectedat time 0 (i.e., within 15 minutes prior to the morning Cystagon® doseadministration), considered as the time of trough cysteamine/peak of WBCcystine after administration of immediate-release cysteamine bitartrate(Cystagon®). One (1) additional PD sample was collected at a sampletimepoint that was time-matched to 1 of 3 PK sample profile times(either 2, 4 or 6 hours) post morning Cystagon® dose. There were sixassociated plasma PK samples collected at time 0 (within 15 minutesprior to morning Cystagon® dose); 30 minutes post morning Cystagon®dose; and 1, 2, 4 and 6 hours (immediately prior to the afternoonCystagon® dose)

Inventive capsule Treatment Assignment: one (1) post-dose PD sample wascollected at time 0.5 hour (30 minutes), considered as the time oftrough cysteamine/peak of WBC cystine after administration of capsulesof CBGB. Two (2) additional PD samples were collected at sampletimepoints that were time-matched to PK sample profile times (either 3,4, 8, 10 or 12 hours) post morning CBGB dose. In order to limit theimpact of autocorrelation, juxtaposed times of sampling for patientstreated with CBGB were not to be taken into account for therandomization. Therefore, patients were randomized to one of thefollowing six pairs of the sampling time points: 3 and 8 hours, 3 and 10hours, 3 and 12 hours, 4 and 8 hours, 4 and 10 hours, 4 and 12 hours.There were nine associated plasma PK samples collected at time 0 (within15 minutes prior to morning CBGB dose), 30 minutes, 2, 3, 4, 6, 8, 10and 12 hours post morning CBGB dose (immediately prior to the eveningCBGB dose).

As recommended in the Cystagon® SmPC, food (meal or snack) was available30 minutes prior to receiving the morning dose and (if applicable) thenext Q6H of Cystagon® administration and the morning dose and Q12H CBGBadministration and (if applicable) the next Q12H CBGB dose. Cystagon®was administered with water and CBGB was administered with an acidicbeverage. Dairy products should have been withheld 1 hour before andafter CBGB dosing.

CBGB-B Study

Administering cysteamine in fasted healthy volunteers provides verystable PK parameters such that it was possible to demonstratebioequivalence between administrations of CBGB capsules as a whole or astheir content sprinkled on food with only 20 healthy volunteers.

The PK parameters of cysteamine were determined after a single dose,first in fasted healthy volunteers, then in patients at steady state,using the model parameters obtained with healthy volunteers as startingparameters for the models in patients. Pharmacokinetic modeling ofcysteamine was based on a 2-compartment model and pharmacodynamicmodeling of WBC cystine was based on an inhibitory E_(max) model.(Belldina, E. B., M. Y. Huang, et al. (2003). “Steady-statepharmacokinetics and pharmacodynamics of cysteamine bitartrate inpaediatric nephropathic cystinosis patients.” Br J Clin Pharmacol 56(5):520-525.)

Since CBGB studies in healthy volunteers were not done againstCystagon®, data in fasted healthy volunteers (Gangoiti, J. A., M.Fidler, et al. (2010). “Pharmacokinetics of enteric-coated cysteaminebitartrate in healthy adults: a pilot study.” Br J Clin Pharmacol 70(3):376-382) were used to determine initial PK model parameters forCystagon®. And data on EC-cysteamine (i.e. Eudragit L50D 55enteric-coated capsules of Cystagon®—a different way of providingdelayed-release cysteamine bitartrate) in this dataset was used forcomparison purposes.

A bioequivalence designed to demonstrate bioequivalence between oraladministration of intact CBGB capsules, and contents of opened CBGBcapsules mixed with applesauce and taken orally. Twenty (20) healthyadults (mean age 37 years, range 19-64 years) received bothpresentations, 8 (75 mg) intact vs. 8 (75 mg) open capsules, in acrossover design study.

The final results are presented in the table below.

No. Population PK, Study/ Subjects Non-Compartmental Analysis2-compartment Model Proto- Entered/ HV/P^(a)) (Pharsight, WinNonLin 6.2)(Pharsight, NLME 1.1) col Com- (Age: C_(max) C_(max)_D AUC_(inf)_D Cl/FCl₂ Coun- Study pleted Mean, Treat- Dose T_(max) (mg/ (mg/ (min*mg/T_(lag) Ka V/F (L/ V₂ (L/ try Design (M/F) Range) ment (mg) (min) L)L/mg) L/mg) (min) (1/min) (L) min) (L) min) UCSD Open (4M/3F)/ P (12,Cysta- 450  75 ± 3.1 ± 0.007 ± 0.88 ± 26 0.029 73 1.07 131 0.41 (USA)label, (4M/3F) 8-17) gon ® 19 1.2 0.003 0.30 Sequen- EC- 450 220 ± 3.2 ±0.007 ± 0.96 ± 156 0.025 98 1.17 54 0.5 tial Cystea- 74 1.4 0.003 0.40mine CBGB- Ran- (24M/ P(12, Cysta- 250-  74 ± 2.6 ± 0.006 ± 0.84 ± 230.025 94 1.1 191 0.5 A dom, 19F)/ 6-26) gon ® 750 32 1.4 0.003 0.31(USA/ Cross- (22M/ CBGB 425- 183 ± 3.5 ± 0.005 ± 1.08 ± 60 0.015 87 1.2200 0.4 EU) over 16F) caps 1300 90 1.7 0.002 0.46 CBGB- Ran- (13M/HV(37, CBGB 600 194 ± 2.3 ± 0.004 ± 0.84 ± 95 0.016 137 1.4 187 0.44 Bdom, 7F)/ 19-64) caps 38 0.6 0.001 0.19 (USA) Cross- (13M/ CBGB 600 190± 2.3 ± 0.004 ± 0.85 ± 98 0.017 151 1.4 192 0.47 over 7F) sprinkled 610.7 0.001 0.21 ^(a))HV = Healthy Volunteers, P = Patients

The conclusion of this population PK modeling on two differentpresentations of CBGB (open and intact), is that the only differencebetween administering CBGB as intact capsules and as open capsules,sprinkled on applesauce, is expressed by the difference between lagtimes: as expected the start of absorption from the beads is stilldelayed (85 min) but slightly less than when the gelatin capsule has tobe dissolved first (108 min) and this has not much of an impact onT_(max) (190 min for open capsules vs. 194 min for intact capsules)since probably only a small amount of beads dissolves early.

However, comparison between the two presentations of CBGB (open andintact) and the immediate-release cysteamine bitartrate (Cystagon®) andthe delayed-release EC-cysteamine, shows that the absorption ofcysteamine after CBGB dosing is not only more delayed (Cystagon®T_(lag)<<CBGB T_(lag)<<EC-cysteamine T_(lag)) but also further extendeddue to a slower absorption (CBGB K_(a)<<Cystagon® K_(a)≈EC-cysteamineK_(a)) compared to EC-cysteamine. Without intending to be bound by anyparticular theory, it is contemplated that the difference in absorptionof the CBGB formulation is related to one or more factors including thedistribution of bead sizes and time-progressive dissolution of multiplebeads and/or the irregularity of bead shapes in the CBGB formulationand/or the distribution of enteric membrane thicknesses in the CBGBformulation.

Example 4 Purity and Stability

Long term stability tests have been performed on the CBGB formulationmade according to Example 1. The major impurity in the CBGB product iscystamine, the well known related substance (dimer).

The use of a more sensitive and less selective method has resulted inthe observation of several impurities found in the CBGB formulation andthe commercial product using cysteamine bitartrate, Cystagon®. Throughthe use of reverse phase HPLC, six peaks observed in the CBGBformulation related substances chromatograms have been identified asproduct degradants (specifically cysteamine bitartrate degradants). Twolots of Cystagon® were evaluated by the same test method. The impuritiesobserved in representative CBGB chromatograms are also observed inCystagon®.

Impurities Assay Method

Cysteamine bitartrate samples are assessed by gradient elution HPLCusing an XBRIDGE C18 column (dimensions: 150 mm×4.6 mm; packing particlesize: 3.5 μm) (Waters, Milford, Mass.). The autosampler temperature is4° C. Approximately 10 μL or approximately 100 μL of sample is injectedonto the column. The column temperature is 40° C. and the sample iseluted at a flow rate of 1.0 mL/min according to the following profile:

HPLC Gradient Time (min) Mobile Phase A (%) Mobile Phase B (%) 0.0 100 02.0 100 0 20.0 60 40 25.0 60 40 25.1 100 0 40.0 100 0

Mobile Phase A contains 23.6 mM 1-octanesulfonic acid sodium and 29.0 mMsodium phosphate (pH 2.6)/acetonitrile/methanol 85/3/12 (v/v/v). MobilePhase B contains 0.20 M 1-octanesulfonic acid sodium and 0.10 M sodiumphosphate (pH 2.6)/acetonitrile/methanol 10/18/72 (v/v/v). The purity of1-octanesulfonic acid is ≧98%. Detection is carried out using a UVdetector at 210 nm.

Reference Solution Preparation.

Reference solutions of Cysteamine Bitartrate Analytical ReferenceStandard are prepared as follows. Working Standard and Working CheckStandard solutions are prepared having a nominal concentration of 0.54mg/mL Cysteamine Bitartrate Analytical Reference Standard in MobilePhase A using low actinic glassware. A Working Sensitivity solution isprepared having a nominal concentration of 0.30 mg/mL CysteamineBitartrate Analytical Reference Standard in Mobile Phase A using lowactinic glassware, which corresponds to the limit of quantification(LOQ) for cysteamine. The water content of the Cysteamine BitartrateAnalytical Reference Standard is determined no more than 7 days beforeuse by Karl Fischer titration or thermal gravimetric analysis (TGA). TheReference Standard is stored refrigerated and blanketed under nitrogen.

Bead Prep Assay Sample Preparation.

Cysteamine Bitartrate Gastro-resistant Beads (CBGB) are prepared foranalysis according to the following procedure. About 3.7 g of CBGB beadsare ground to a fine powder using a ball mill for approximately 1 minuteat 27 Hz. The grind is transferred to an amber bottle for storage. StockBead Prep Assay sample solutions are prepared in duplicate by adding370.4 mg±5 mg of the grind to a 250 mL low actinic volumetric flask anddiluting with Mobile Phase A. The mixture is stirred with a stir bar forat least 15 minutes. Approximately 15 mL of the resulting solution isfiltered through a 0.45 μm nylon filter, with the first 5 mL beingdiscarded. The cysteamine concentration of the resulting Stock Bead PrepAssay sample solution is approximately 0.300 mg/mL. Working Bead Prepsample solutions are prepared by placing 4.0 mL of Stock Bead Prep Assaysample solution in a 25 mL low actinic volumetric flask and diluting tovolume with Mobile Phase A. The cysteamine concentration of theresulting Working Bead Prep sample solution is approximately 0.048mg/mL.

Assay Sample Preparation.

CBGB capsules are prepared for analysis according to the followingprocedure. To reduce exposure to light and oxygen, sample preparation(from the initial weighing of the full capsules to the loading of samplevials on the HPLC) is completed in one day. Ten capsules are weighed.The capsule contents are emptied and the empty shells are weighed todetermine the average capsule fill weight. The capsule contents areground to a fine powder using a ball mill for approximately 1 minute at27 Hz. The grind is transferred to an amber bottle for storage. Stocksample solutions are prepared in duplicate by adding the appropriateamount of the grind for 1 capsule (as determined by the average capsulefill weight) to a 25 mL low actinic volumetric flask and diluting withMobile Phase A. The mixture is stirred with a stir bar for at least 15minutes. The resulting solution is centrifuged at about 3400 rpm for 5minutes. Approximately 15 mL of the centrifuged solution is filteredthrough a 0.45 μm nylon filter (Acrodisc, 25 mm diameter), with thefirst 5 mL being discarded, to obtain Stock sample solutions. Workingsample solutions are prepared by placing 6.0 mL of Stock sample solution(for 25 mg capsules) or 2.0 mL of Stock sample solution (for 75 mgcapsules) in a 10 mL low actinic volumetric flask and diluting to volumewith Mobile Phase A.

Content Uniformity Sample Preparation.

CBGB capsules are prepared for analysis according to the followingprocedure. To reduce exposure to light and oxygen, sample preparation(from the initial weighing of the full capsules to the loading of samplevials on the HPLC) is completed in one day. Ten capsules are weighed.The contents of each capsule are emptied into separate mortars and theempty shells are weighed to determine the individual capsule fillweight. About 1-2 mL of Mobile Phase A is added into the mortar. Thebeads are immediately ground to a paste. If needed, additional MobilePhase A is added to the paste, up to 5 mL total. The paste istransferred to a 250 mL low actinic volumetric flask. The mortar andpestle are thoroughly rinsed with Mobile Phase A and the rinse solutionis collected in to the same flask. The flask is filled aboutthree-quarters full with Mobile Phase A and stirred for at least 15minutes. The flask is filled to volume with Mobile Phase A.Approximately 20 mL of the resulting solution is filtered through a 0.45μm nylon filter (Acrodisc, 25 mm diameter), with the first 5 mL beingdiscarded, to obtain Stock CU sample solutions. Working CU samplesolutions are prepared by placing 12.0 mL of Stock CU sample solution(for 25 mg capsules) or 4.0 mL of Stock CU sample solution (for 75 mgcapsules) in a 25 mL low actinic volumetric flask and diluting to volumewith Mobile Phase A. The cysteamine concentration of the resultingWorking CU sample solutions is approximately 0.048 mg/mL.

Data Analysis.

The cysteamine Working Standard solution concentration is calculatedaccording to the following equation: Cysteamine Concentration(C_(Std))=mg Cysteamine Bitartrate Analytical ReferenceStandard×P_(f)/25.0 mL

P_(f) represents a purity factor for the standard material. P_(f) iscalculated according to the following equation:

P _(f) =B×(100−Water)×C/100

where B=the anhydrous cysteamine free base in the Cysteamine BitartrateAnalytical Reference Standard (expressed as a decimal value on thestandard bottle label),water=the water content as determined by Karl Fischer or TGA no morethan 7 days before use (expressed as a percentage), andC=the cystamine correction (expressed as a decimal value on the standardbottle label).

The amount of cysteamine per capsule is calculated according to thefollowing equation:

mg cysteamine per capsule=(A _(Sam) /A _(Std))×C _(Std)×DF×(AveWt/SamWt)

where A_(Sam)=the peak area of cysteamine in the sample chromatogramwith a 10 μL injection,A_(Std)=the average peak area of cysteamine in all Working Standardsolution chromatograms with a 10 μL injection,C_(Std)=the concentration (mg/mL) of cysteamine in the Working Standardsolution, DF=the dilution factor (125 for 75 mg capsules; 41.6667 for 25mg capsules),AveWt=the average capsule fill weight (mg), andSamWt=the sample weight (mg).

For Content Uniformity, the amount of cysteamine per capsule iscalculated according to the following equation:

mg cysteamine per capsule=(A _(Sam) /A _(Std))×C _(Std)×DF

where A_(Sam)=the peak area of cysteamine in the sample chromatogramwith a 10 μL injection,A_(Std)=the average peak area of cysteamine in all Working Standardsolution chromatograms with a 10 μL injection,C_(Std)=the concentration (mg/mL) of cysteamine in the Working Standardsolution, andDF=the dilution factor (1562.5 for 75 mg capsules; 520.8 for 25 mgcapsules).

For the Bead Prep Assay, the amount of cysteamine per capsule iscalculated according to the following equation:

mg cysteamine per capsule=(A _(Sam) /A _(Std))×C _(Std)×DF×(AveWt/SamWt)

where A_(Sam)=the peak area of cysteamine in the sample chromatogramwith a 10 μL injection,A_(Std)=the average peak area of cysteamine in all Working Standardsolution chromatograms with a 10 μL injection,C_(Std)=the concentration (mg/mL) of cysteamine in the Working Standardsolution,DF=the dilution factor (use the 75 mg Dilution Factor, 1562.5),AveWt=the average capsule fill weight (mg) (use the target fill weight,370.4 mg), andSamWt=the sample weight (mg) (use the actual weight used in samplepreparation).

The percentage of the label claim (% LC) is calculated for the Assay,Content Uniformity, and Bead Prep Assay sample solutions according tothe following equation:

% LC=(mg cysteamine)/LC×100%

where mg cysteamine=the amount calculated by the applicable equationabove, andLC=the amount of the label claim (75 mg or 25 mg) (use 75 mg for theBead Prep Assay).

The amount of substances related to cysteamine bitartrate (includingcysteamine impurities) such as cystamine is calculated according to thefollowing equation:

mg related substance=(A _(RS) /A _(Std))×(C _(Std)/RRF)×DF×(AveWt/SamWt)

where A_(RS)=the peak area of any related substance in the Workingsample solution chromatogram with a 100 μL injection (peaks before RRT0.48 are disregarded; peaks observed in the chromatogram of the secondinjection of Mobile Phase A/Blank (100 μL injection) are alsodisregarded),A_(Std)=the average peak area of cysteamine in all Working Standardsolution chromatograms with a 10 μL injection,C_(Std)=the concentration (mg/mL) of cysteamine in the Working Standardsolution,RRF=the relative response factor (0.98 for cystamine; 1.00 for otherrelated substances),DF=the dilution factor (12.5 for 75 mg capsules; 4.16667 for 25 mgcapsules),AveWt=the average capsule fill weight (mg), andSamWt=the weight the sample grind from the Working sample solutionpreparation (mg).

The weight percentage of cystamine and other individual relatedsubstances is determined according to the following equation:

% individual related substance=mg related substance/mg cysteamine×100%

where mg related substance=the amount of related substance calculatedabove, andmg cysteamine=the amount of cysteamine for the Assay sample.

The percentage of total related substances is determined by summing allrelated substances greater than or equal to 0.05%. Peaks after 28minutes are disregarded. In contrast to a previous electrochemicaldetection method that disregarded early-eluting peaks as not relevant tothe purity calculation, the foregoing method determines that early peaksare impurities and integrates early-eluting peaks as described above.

Results

Two lots of Cystagon® were dispensed in standard pharmacy containers andverified to be well within the manufacturer's expiration date. One lotwas provided by a healthcare provider. It was dispensed in a standardpharmacy bottle and verified by the healthcare provider to be wellwithin the expiration date. Upon analysis by the Test Method, it wasshown to contain 9.1% cystamine by weight and 10.3% total relatedsubstances, based on the weight of cysteamine, using the assay describedabove. The second analyzed Cystagon® lot was identified by lot number.Upon analysis by the assay described above, it was shown to contain 5.2%cystamine by weight and 5.7% total related substances, based on theweight of cysteamine. Each Cystagon® lot was shipped and stored underspecified label conditions.

Two representative lots of the CBGB capsule formulation were analyzed bythe assay described above and were shown to contain 3.7% cystamine byweight and 3.6% cystamine by weight, respectively, based on the weightof cysteamine, at the time of manufacture. For both lots, the totalamount of related substances was 4.2% by weight, based on the weight ofcysteamine.

The CBGB product lots were put on stability testing in various packagesand storage conditions, then assayed for purity using the assaydescribed above. The results are shown in the table below

Product Conditions dose/count/ ° C./% Cystamine %/total relatedsubstances at time point (month) Lot bottle size RH Initial 1 2 3 6 9 121 75 mg/60/100 cc 25/60 3.7/4.2 3.7/NA 3.1/NA 3.4/4.2 3.5/4.4 3.7/5.13.8/5.5 1 75 mg/60/100 cc 40/75 3.7/4.2 3.7/NA 3.2/NA 3.5/7.9  3.9/12.31 75 mg/150/250 cc 25/60 3.7/4.2 3.5/NA 3.4/NA 3.7/4.5 3.6/4.3 3.6/4.93.7/5.4 1 75 mg/150/250 cc 40/75 3.7/4.2 3.4/NA 3.4/NA 3.7/7.9  3.8/11.61 75 mg/300/400 cc 25/60 3.7/4.2 3.5/NA 3.3/NA 3.4/4.2 3.5/4.4 3.7/5.13.8/5.7 1 75 mg/300/400 cc 40/75 3.7/4.3 3.4/NA 3.2/NA 3.6/7.7  4.0/12.81 75 mg/60/bulk 25/40 3.7/4.2 3.4/NA 3.4/NA 3.2/NA 3.3/4.2 3.3/4.53.2/4.6 1 75 mg/60/bulk 40/75 3.7/4.2 3.4/NA 3.2/NA 3.3/NA 2.9/9.1 2 75mg/150/250 cc 25/60 3.6/4.2 3.1/4.0 3.3/4.3 3.0/4.3 3.3/5.0 2 75mg/150/250 cc 40/75 3.6/4.2 3.1/7.5  3.6/12.1

Additional CBGB product samples according to Example 1 were put on longterm stability testing in various packages and storage conditions, thenassayed for purity using the assay described above. Results are shown inthe table below.

Product dose/count/bottle Conditions Cystamine %/total relatedsubstances at time point (month) Lot size ° C./% RH Initial 1 2 3 6 9 1215 18 24 3 25 mg/60/50 25/60 3.2/ 3.0/ 3.3/ 3.1/ 3.3/ 3.2/ 3.6/ NA 4.0/4.6/ cc 4.1 NA NA 4.2 4.7 4.9 5.5 6.8 NA 3 25 mg/60/50 40/75 3.2/ 2.9/3.0/ 3.0/ 3.7/ cc 4.1 NA NA 7.8 13.4 4 75 mg/150/ 25/60 3.2/ 3.2/ 3.4/3.4/ 3.7/ 3.5/ 4.1/ NA 4.2/ 4.7/ 250 cc 4.0 NA NA 4.7 5.2 5.3 6.3 7.1 NA4 75 mg/150/ 40/75 3.2/ 3.1/ 3.4/ 3.5/ 4.0/ 250 cc 4.0 NA NA 9.0 13.8 575 mg/60/100 25/60 3.4/ 3.4/ 3.5/ 3.3/ 3.7/ 3.5/ 5.0/ 3.9/ 3.9/ 5.3/ cc4.2 NA NA 4.4 5.2 5.2 NA 6.0 NA NA 5 75 mg/60/100 40/75 3.4/ 3.3/ 3.4/3.3/ 4.1/ cc 4.2 NA NA 8.5 16.0¹ 5 75 mg/300/ 25/60 3.4/ 3.5/ 3.5/ 3.5/4.0/ 3.3/ 5.3/ 4.1/ 4.1/ 5.3/ 400 cc 4.2 NA NA 4.9 6.0 5.3 NA 6.5 NA NA5 75 mg/300/ 40/75 3.4/ 3.5/ 3.7/ 3.7/ 4.2/ 400 cc 4.2 NA NA 9.6 15.4¹ 575 mg/60/bulk 25/60 3.4/ 3.5/ 3.5/ 3.4/ 3.7/ 3.2/ 4.1/ 4.2 NA NA NA 5.2NA 5.5 5 75 mg/60/bulk 40/75 3.4/ 3.4/ 3.4/ 3.1/ 3.0/ 4.2 NA NA NA 11.26 25 mg/60/50 25/60 3.3/ 3.3/ 3.2/ 3.2/ 3.7/ 3.3/ 4.0/ 3.9/ 4.4/ 5.1/ cc4.1 NA NA 4.3 5.5 5.0 NA 5.9 NA NA 6 25 mg/60/50 40/75 3.3/ 3.2/ 3.1/3.0/ 3.8/ cc 4.1 NA NA 7.8 15.7¹ 6 25 mg/420/ 25/60 3.3/ 3.3/ 3.5/ 3.6/4.0/ 3.8/ 4.6/ 4.8/ 4.1/ 5.2/ 250 cc 4.1 NA NA 4.9 6.0 5.9 NA 7.4 NA NA6 25 mg/420/ 40/75 3.3/ 3.4/ 3.5/ 3.5/ 4.7/ 250 cc 4.1 NA NA 9.7 17.1¹ 625 mg/60/bulk 25/60 3.3/ 3.4/ 3.4/ 3.3/ 3.7/ 3.1/ 3.5 4.1 NA NA NA 5.4NA 5.3 6 25 mg/60/bulk 40/75 3.3/ 3.3/ 3.2/ 2.9/ 2.9 4.1 NA NA NA 11.4 775 mg/60/100 25/60 3.2/ 3.2/ 3.3/ 3.3/ 3.5/ 3.2/ 4.6/ 4.1/ 3.6/ 4.6/ cc3.9 NA NA 4.5 5.3 4.9 NA 6.1 NA NA 7 75 mg/60/100 40/75 3.2/ 3.2/ 3.1/3.2/ 3.7/ cc 3.9 NA NA 8.0 13.5¹ 7 75 mg/300/ 25/60 3.2/ 3.4/ 3.4/ 3.4/3.7/ 3.4/ 4.9/ 4.2/ 3.8/ 4.7/ 400 cc 3.9 NA NA 4.8 5.5 5.2 NA 6.4 NA NA7 75 mg/300/ 40/75 3.2/ 3.3/ 3.3/ 3.5/ 3.9/ 400 cc 3.9 NA NA 9.1 13.6¹ 775 mg/60/bulk 25/60 3.2/ 3.3/ 3.3/ 3.2/ 3.5/ 2.9/ 4.0/ 3.9 NA NA NA 5.2NA 5.5 7 75 mg/60/bulk 40/75 3.2/ 3.2/ 3.2/ 2.9/ 2.8/ 3.9 NA NA NA 10.38 25 mg/60/50 25/60 3.1/ 3.1/ 3.1/ 3.0/ 3.4/ 3.1 3.7 3.4/ 3.4/ 4.3/ cc3.9 NA NA 4.1 4.9 4.9 NA 5.3 NA NA 8 25 mg/60/50 40/75 3.1/ 3.0/ 2.9/2.7/ 3.4/ cc 3.9 NA NA 7.4 13.4¹ 8 25 mg/420/ 25/60 3.1/ 3.2/ 3.3/ 3.3/3.6/ 3.4/ 4.1/ 4.5/ 3.8/ 4.6/ 250 cc 3.9 NA NA 4.6 5.3 5.0 NA 6.8 NA NA8 25 mg/420/ 40/75 3.1/ 3.3/ 3.3/ 3.2/ 4.0/ 250 cc 3.9 NA NA 9.1 16.2¹ 825 mg/60/bulk 25/60 3.1/ 3.3/ 3.2/ 3.1/ 3.3/ 3.0/ 3.4/ 3.9 NA NA NA 4.7NA 4.9 8 25 mg/60/bulk 40/75 3.1/ 3.2/ 3.0/ 2.8/ 2.7/ 3.9 NA NA NA 10.69 25 mg/60/50 25/60 3.6/ 3.5/ 2.9/ 3.2/ 3.4/ 3.3/ 3.4/ cc 4.2 NA NA 4.04.4 4.6 5.0 9 25 mg/60/50 40/75 3.6/ 3.4/ 2.7/ 3.0/ 3.4/ cc 4.2 NA NA6.8 11.4 9 25 mg/420/ 25/60 3.6/ 3.5/ 3.0/ 3.4/ 3.4/ 3.5/ 3.8/ 250 cc4.2 NA NA 4.3 4.4 5.0 5.8 9 25 mg/420/ 40/75 3.6/ 3.5/ 3.0/ 3.5/ 3.8/250 cc 4.2 NA NA 7.9 12.9 9 25 mg/60/bulk 25/40 3.6/ 3.5/ 3.0/ 3.3/ 3.3/3.1/ 3.1/ 4.2 NA NA NA 4.2 4.2 4.6 9 25 mg/60/bulk 40/75 3.6/ 3.3/ 2.8/3.0/ 2.8/ 4.2 NA NA NA 9.1 10 25 mg/60/50 25/60 3.4/ NA NA 3.1/ 3.1/2.9/ 3.1/ cc 4.0 3.9 4.1 4.2 4.7 10 25 mg/60/50 40/75 3.4/ NA NA 2.7/3.2/ cc 4.0 7.0 11.9 ¹Samples pulled at 6 months but held at roomtemperature until new reference standard was qualified (at 8 months)

All of the foregoing CBGB samples met the acid resistance criteria (Notmore than 10% (Q) of the label claim of cysteamine is dissolved after 2hours in 0.1N HCl) and dissolution criteria (Not less than 70% (Q) ofthe label claim of cysteamine is dissolved after 30 minutes in 0.2Msodium phosphate buffer, pH 6.8)

The foregoing description is given for clearness of understanding only,and no unnecessary limitations should be understood therefrom, asmodifications within the scope of the invention may be apparent to thosehaving ordinary skill in the art.

Throughout this specification and the claims which follow, unless thecontext requires otherwise, the word “comprise” and variations such as“comprises” and “comprising” will be understood to imply the inclusionof a stated integer or step or group of integers or steps but not theexclusion of any other integer or step or group of integers or steps.

Throughout the specification, where compositions are described asincluding components or materials, it is contemplated that thecompositions can also consist essentially of, or consist of, anycombination of the recited components or materials, unless describedotherwise. Likewise, where methods are described as including particularsteps, it is contemplated that the methods can also consist essentiallyof, or consist of, any combination of the recited steps, unlessdescribed otherwise. The invention illustratively disclosed hereinsuitably may be practiced in the absence of any element or step which isnot specifically disclosed herein.

The practice of a method disclosed herein, and individual steps thereof,can be performed manually and/or with the aid of or automation providedby electronic equipment. Although processes have been described withreference to particular embodiments, a person of ordinary skill in theart will readily appreciate that other ways of performing the actsassociated with the methods may be used. For example, the order ofvarious of the steps may be changed without departing from the scope orspirit of the method, unless described otherwise. In addition, some ofthe individual steps can be combined, omitted, or further subdividedinto additional steps.

All patents, publications and references cited herein are hereby fullyincorporated by reference. In case of conflict between the presentdisclosure and incorporated patents, publications and references, thepresent disclosure should control.

1. A pharmaceutical dosage form, comprising a plurality of cysteaminebeads, the beads comprising a core particle comprising cysteamine or apharmaceutically acceptable salt thereof and a pharmaceuticallyacceptable excipient, and an enteric membrane surrounding the core,wherein the plurality of beads is characterized by a distribution ofparticle sizes.
 2. A pharmaceutical dosage form comprising a pluralityof cysteamine beads, the beads comprising a core particle includingcysteamine or a pharmaceutically acceptable salt thereof and apharmaceutically acceptable excipient, and an enteric membranesurrounding the core, wherein the plurality of beads is characterized bya distribution of enteric membrane thicknesses.
 3. The pharmaceuticalcomposition of claim 1, wherein the particle sizes of the beads are in arange of about 0.7 mm to about 2.5 mm.
 4. The pharmaceutical dosage formof claim 1, wherein the distribution of bead sizes is characterized byat least 80% by weight of the beads having a particle size in a range ofabout 850 μm to about 1180 μm.
 5. The pharmaceutical composition ofclaim 1, wherein 5% or less of the beads by weight are retained on a #12mesh (1.68 mm) screen and 10% or less by weight pass through a #20 mesh(0.84 mm) screen.
 6. The pharmaceutical composition of claim 1, whereinthe distribution of bead sizes is characterized by less than 5% byweight of the beads being retained on a 1400 μm sieve.
 7. Thepharmaceutical dosage form of claim 1, wherein the distribution of beadsizes is characterized by less than 30% by weight of the beads beingretained on a 1180 μm sieve.
 8. The pharmaceutical dosage form of claim1, wherein the distribution of bead sizes is characterized by less than70% by weight of the beads being retained on a 1000 μm sieve.
 9. Thepharmaceutical dosage form of claim 1, wherein the distribution of beadsizes is characterized by less than 20% by weight of the beads beingretained on a 850 μm sieve.
 10. The pharmaceutical dosage form of claim1, wherein the distribution of bead sizes is characterized by at least15% by weight of the beads being retained on a 1180 μm sieve.
 11. Thepharmaceutical dosage form of claim 1, wherein the distribution of beadsizes is characterized by at least 50% by weight of the beads beingretained on a 1000 μm sieve.
 12. The pharmaceutical dosage form of claim1, wherein the distribution of bead sizes is characterized by at least10% by weight of the beads being retained on a 850 μm sieve.
 13. Thepharmaceutical dosage form of claim 1, wherein the distribution of beadsizes is characterized by a median particle size in a range of about 850μm to about 1180 μm.
 14. (canceled)
 15. The pharmaceutical dosage formof claim 1, wherein the bead core particle excipient comprises a fillerand a binder.
 16. The pharmaceutical dosage form of claim 1, wherein thecysteamine (as free base) is present in the bead core particle in anamount of at least 10 wt. %.
 17. The pharmaceutical dosage form of claim1, wherein the cysteamine as the bitartrate salt is present in the beadcore particle in an amount of at least 50 wt. %.
 18. The pharmaceuticaldosage form of claim 1, wherein the cysteamine or pharmaceuticallyacceptable salt thereof is cysteamine bitartrate.
 19. The pharmaceuticaldosage form of claim 1, wherein the enteric membrane is present in anamount in a range of about 20% to about 40% weight gain, based on theweight of the bead core particles.
 20. The pharmaceutical dosage form ofclaim 1, wherein 5% or less of the bead core particles by weight areretained on a #12 mesh (1.68 mm) screen and 10% or less by weight passthrough a #20 mesh (0.84 mm) screen.
 21. The pharmaceutical dosage formof claim 1, wherein the enteric-coated beads are characterized by acidresistance such that not more than 10% of the cysteamine in the beads isdissolved after a period of two hours in a 0.1N HCl solution.
 22. Thepharmaceutical dosage form of claim 1, wherein the enteric-coated beadsare characterized dissolution such that 80% of the cysteamine orpharmaceutically acceptable salt thereof is released within 20 minutesin a solution buffered at pH 6.8.
 23. The pharmaceutical dosage form ofclaim 1, further comprising a capsule shell enclosing the plurality ofbeads.
 24. The pharmaceutical dosage form of claim 1, characterized by amean Tmax upon oral dosing of greater than 75 minutes.
 25. Thepharmaceutical dosage form of claim 1, characterized by a mean Cmax uponoral dosing in a range of about 22.16 μmol/L to about 34.63 μmol/L,normalized to a 450 mg dose.
 26. The pharmaceutical dosage form of claim1, characterized by a mean AUC (0-6 hours) upon oral dosing in a rangeof about 60.74 μmol·h/L to about 94.91 μmol·h/L, normalized to a 450 mgdose.
 27. The pharmaceutical dosage form of claim 1, characterized by amean AUC (0-12 hours) upon oral dosing in a range of about 79.41μmol·h/L to about 124.08 μmol·h/L, normalized to a 450 mg dose.
 28. Thepharmaceutical dosage form of claim 1, characterized by the dosage formwhen administered orally in a hard capsule shell being bioequivalent tothe plurality of beads administered orally without a capsule shell. 29.The pharmaceutical dosage form of claim 1, characterized by the dosageform when administered orally in a hard capsule shell exhibiting a Cmaxin a range of 80% to 125% of Cmax exhibited by the plurality of beadsadministered orally without a capsule shell.
 30. The pharmaceuticaldosage form of claim 1, characterized by the dosage form whenadministered orally in a hard capsule shell exhibiting an AUC (0-12 h)or AUC (0-inf) in a range of 80% to 125% of that exhibited by theplurality of beads administered orally without a capsule shell.
 31. Apharmaceutical dosage form, comprising a plurality of cysteamine beads,the beads comprising a core particle comprising cysteamine bitartrate,and an enteric membrane surrounding the core, the dosage formcharacterized by providing mean pharmacokinetic parameters upon oraldosing, fasted, of: Tmax 194±38 minutes, Cmax 2.3±0.6 mg/L, and/or AUC(0-inf_D) 0.84±0.19 min*mg/L/mg, or a bioequivalent Tmax, Cmax or AUC ina range of 80% to 125%, or 80% to 120% of such reference parameter. 32.(canceled)
 33. The pharmaceutical dosage form of claim 1, characterizedby having less than 5 wt. % cystamine, based on the amount ofcysteamine, following storage at 25° C. and 40% relative humidity for 12months, as determined by reverse phase HPLC with UV detection at 210 nm.34. The pharmaceutical dosage form of claim 1, characterized by havingless than 5 wt. % cystamine, based on the amount of cysteamine,following storage at 25° C. and 60% relative humidity for 6 months, asdetermined by reverse phase HPLC with UV detection at 210 nm.
 35. Thepharmaceutical dosage form of claim 1, characterized by having less than5 wt. % cystamine, based on the amount of cysteamine, following storageat 40° C. and 75% relative humidity for 3 months, as determined byreverse phase HPLC with UV detection at 210 nm.
 36. (canceled)
 37. Thepharmaceutical dosage form of claim 1, the beads comprising a coreparticle comprising cysteamine bitartrate, a filler, a binder, and anenteric membrane surrounding the core, wherein the plurality of beads ischaracterized by a distribution of particle sizes in a range of about0.7 mm to about 2.5 mm; wherein the enteric membrane is present in anamount in a range of about 20% to about 40% based on the weight of thebead core particles; and wherein the beads are disposed in a capsuleshell.
 38. A method of treating a patient in need of cysteaminecomprising administering to the patient a dosage form according toclaim
 1. 39. A method for the preparation of the dosage form of claim 1,comprising coating a core particle comprising cysteamine or apharmaceutically acceptable salt thereof and an excipient with anenteric polymer to form the enteric membrane.
 40. (canceled) 41.(canceled)
 42. (canceled)
 43. (canceled)
 44. (canceled)
 45. (canceled)46. (canceled)
 47. (canceled)
 48. (canceled)